Microsoft is gaining market share, but at a very high cost. Bing has had the living hell marketed out of it, particularly on television. If all that money creates converts who consistently use Bing over Google, and market share keeps growing, it’ll be worth the cost. Right now I’m guessing whatever money Microsoft is earning from Bing is dwarfed by the search engine’s marketing budget. Microsoft has a long and proud history of losing a ton of money in a market area they want to enter and challenge a rival (see: Xbox gaming console.)

Now let’s look at the actual numbers and see just how far behind Google Bing really is, and how it may not be chipping away at the targeted rival at all, but actually stealing market share from its now partner, Yahoo.

From the first link:

December 2009

January 2010

February 2010

Google

72.25%

71.49%

70.95%

Yahoo

14.83%

14.57%

14.57%

Bing

8.92%

9.37%

9.70%

Source: Hitwise

And:

January 2010

February 2010

Google

65.4%

65.5%

Yahoo

17.0%

16.8%

Bing

11.3%

11.5%

Source: comScore

Also from the first link:

Bing search engine may still be a bit player in the lucrative online search business dominated byGoogle, but it’s slowly and steadily gaining users. And it appears that Bing’s share is coming at the expense of both Google (GOOG) and Yahoo, the latter of which recentlyteamed up with Microsoft to be more competitive in online search.

A commenter at the link made a great point that some of this gain could be from Windows 7 users retaining — at least for now — the Bing default search engine option.